How to use the pikepdf.Pdf function in pikepdf

def sandwich(resources):
    # Has XMP, docinfo, , shorthand attribute XMP
    return Pdf.open(resources / 'sandwich.pdf')

def first_image_in(filename):
    pdf = Pdf.open(filename)
    pdfimagexobj = next(iter(pdf.pages[0].images.values()))
    return pdfimagexobj, pdf

def congress(resources):
    pdf = Pdf.open(resources / 'congress.pdf')
    pdfimage = pdf.pages[0].Resources.XObject['/Im0']
    return pdfimage, pdf

def test_pdfa_modify(resources, outdir):
    sandwich = resources / 'sandwich.pdf'
    assert verapdf_validate(sandwich)

    pdf = Pdf.open(sandwich)
    with pdf.open_metadata(update_docinfo=False, set_pikepdf_as_editor=False) as meta:
        pass
    pdf.save(outdir / '1.pdf')
    assert verapdf_validate(outdir / '1.pdf')

    pdf = Pdf.open(sandwich)
    with pdf.open_metadata(update_docinfo=False, set_pikepdf_as_editor=True) as meta:
        pass
    pdf.save(outdir / '2.pdf')
    assert verapdf_validate(outdir / '2.pdf')

    pdf = Pdf.open(sandwich)
    with pdf.open_metadata(update_docinfo=True, set_pikepdf_as_editor=True) as meta:
        meta['dc:source'] = 'Test'
        meta['dc:title'] = 'Title Test'
    pdf.save(outdir / '3.pdf')
    assert verapdf_validate(outdir / '3.pdf')

def test_pdfa_sanity(resources, outdir):
    filename = resources / 'veraPDF test suite 6-2-10-t02-pass-a.pdf'

    assert verapdf_validate(filename)

    pdf = Pdf.open(filename)
    pdf.save(outdir / 'pdfa.pdf')

    assert verapdf_validate(outdir / 'pdfa.pdf')
    assert pdf.open_metadata().pdfa_status == '1B'

def inline(resources):
    pdf = Pdf.open(resources / 'image-mono-inline.pdf')
    for operands, _command in parse_content_stream(pdf.pages[0]):
        if operands and isinstance(operands[0], PdfInlineImage):
            return operands[0], pdf

def enron1(resources):
    # Has nuls in docinfo, old PDF
    return Pdf.open(resources / 'enron1_gs.pdf')

def optimize(input_file, output_file, context, save_settings):
    log = context.log
    options = context.options
    if options.optimize == 0:
        safe_symlink(input_file, output_file)
        return

    if options.jpeg_quality == 0:
        options.jpeg_quality = DEFAULT_JPEG_QUALITY if options.optimize < 3 else 40
    if options.png_quality == 0:
        options.png_quality = DEFAULT_PNG_QUALITY if options.optimize < 3 else 30
    if options.jbig2_page_group_size == 0:
        options.jbig2_page_group_size = 10 if options.jbig2_lossy else 1

    with pikepdf.Pdf.open(input_file) as pike:
        root = Path(output_file).parent / 'images'
        root.mkdir(exist_ok=True)

        jpegs, pngs = extract_images_generic(pike, root, log, options)
        transcode_jpegs(pike, jpegs, root, log, options)
        # if options.optimize >= 2:
        # Try pngifying the jpegs
        #    transcode_pngs(pike, jpegs, jpg_name, root, log, options)
        transcode_pngs(pike, pngs, png_name, root, log, options)

        jbig2_groups = extract_images_jbig2(pike, root, log, options)
        convert_to_jbig2(pike, jbig2_groups, root, log, options)

        target_file = Path(output_file).with_suffix('.opt.pdf')
        pike.remove_unreferenced_resources()
        pike.save(target_file, **save_settings)